Blood-shot eyes show either inflammation of them or fulness of blood in the head, which is often present in fevers. If one eye only is very red, of course the trouble must be in itself. Yellowness of the "whites " of the eyes occurs in bilious disorder.

The eyelids are notably prominent in that curious and rather uncommon disorder called " exophthalmic goitre." Prominence or bulging of one eye only shows a probability of disease, as a tumor, behind that eye.

Sinking of the eyeballs in their sockets is seen to some extent in consumption and other wasting diseases. Sinking of one eye must result from wasting of its own substance or of the socket behind it, the former being often observed in the blind.

Rolling of the eyes from side to side is common in great nervous restlessness of infants or young children.

Squinting, which is natural with some, and an acquired habit with others, becomes a serious symptom when it occurs as the result of disease of the brain.

The lustre of the eyes grows dull often a short time, perhaps a few hours, before death. Bright eyes are commonly noticed in advancing consumption. They may glare in mania (insanity), or, for a time, in acute inflammation of the brain.

Very small pupils of the eyes are seen when either they are, or the brain is, the seat of inflammation. In opium-poisoning the pupils are contracted, at least until very near death. They are large (dilated), commonly, in apoplexy, water on the brain (hydrocephalus), and poisoning by prussic acid or by Jamestown weed (stramonium) or belladonna.

Great shrinking from light (photophobia) exists in severe inflammation of the eyes and also in acute inflammation of the brain

Spots, rings, etc., floating before the sight (muscæ volitantes) show the presence of opaque particles in the interior of the eyeball (vitreous humor), which are not of much importance. Fixed dark spots are of more consequence; they often show a beginning of blindness.